JP2017017819A - Power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost power supply system effective for reducing the environmental burden due to power demand.SOLUTION: By a system configuration where the charger and power conversion inverter of a power storage system are characteristic as the center of power supply, permanent cut of the demand peak of a system power supply is achieved. Furthermore, since low price is achieved by a configuration where a solar panel is not essential, introduction is facilitated, and a power supply system expected to spread widely is obtained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system comprising a large-capacity storage battery, a charger and an inverter for home and office in particular.

JP2015-065740: Optimal control method for smart house

With regard to Patent Document 1, however, in order to realize self-sufficiency of electric power by natural energy power generation that is ideal, no matter how much efficiency of power consumption is promoted, solar power generation and wind power generation that are supply sources depend on conditions As long as it is an unstable power source with zero power generation, it cannot be a fundamental measure.
A method that makes the best use of the characteristics of the storage battery while using the system power source, which is the most stable power supply source at present, is more realistic and is the best method.

  As power supply equipment to be installed in homes and the like called conventional general smart houses in Japan, solar panels and fuel cells or storage battery systems such as ENE-FARM are common. In the case of an apartment where installation of panels is impossible or a house where installation is impossible due to inappropriate sun angle, none of these will be introduced. Full-fledged popularization of power supply equipment for smart houses as an environmental measure is the goal.

From the viewpoint of reducing environmental impact, natural energy power generation facilities are being introduced, and the most common and mass-installed facilities are solar panels. In addition, there is a fatal drawback that it does not generate electricity in the rain, and it is not a fundamental measure that can replace fossil fuel thermal power generation.
In addition, during power generation, general electric utilities may refuse to connect to the system power supply due to the load on the transmission line due to the large amount of generated power, which also hinders the spread of the power supply. Yes.
In order to compensate for the above-mentioned drawbacks, there is a means to alleviate the peak of power supply and demand by introducing a fuel cell or storage battery system such as ENE-FARM at the same time together with a solar panel, but these are expensive facilities. In order to introduce a plurality at the same time, a huge initial cost is required.

Regarding the power storage system, the number of products is increasing and the price is also decreasing and it is easy to introduce, but the specifications are insufficient, such as the output at the time of power outage is about 1500W and even the operation of one vacuum cleaner is not guaranteed It is. Furthermore, when the maximum output is exceeded, the power supply is completely stopped as a safety measure. A situation where the power supply, which is one of the lifelines, suddenly stops must be avoided as much as possible.
As a means to make up for this drawback, the output line is divided into two parts at the time of installation of the power storage system, one of which is for an important load that does not interrupt power during a power failure, and the other is for a general load that stops output in the event of a power failure However, as a result, the work of wiring the building is cumbersome, increasing the number of man-hours, and increasing the cost.
Also for users, there are two types of outlets with different specifications, which can be confusing.

  The ultimate ideal for future global warming and environmental issues such as CO2 reduction is to realize self-sufficiency of electricity by natural energy generation without relying on system power supply in homes. A system based on an unstable power generation device that depends on the weather and the like, and a power supply system composed of a power storage system that is not functionally functional despite its high cost, cannot be realized or even predicted.

  The present invention has an object to provide a power supply system that realizes a form close to an ideal function in spite of the low cost specification that promotes the spread in the above situation.

In order to achieve the above object, a power supply system according to claim 1 of the present invention has conventionally used power supplied from a system power source, a solar power generation system, a power storage system, and the like together to supply power to a power supply area such as a home. What has been provided is that power is provided only from the inverter output of the power storage system, and the system power supply is used only for charging the storage battery.
By adopting this method, even when the power used varies in the power supply area, the charging power is maintained almost constant with the rated value as the upper limit, so that a permanent peak cut can be performed on the system power supply. .
Since the inverter in the present invention bears all of the supplied power, the rated output of the inverter is the rated power that can be used in the supply area. Thereby, electric power larger than contract electric power with a general electric utility can be used. In addition, the basic charge can be reduced by reviewing the contract current and changing to a constant current contract as much as possible.

The fail-safe inverter according to claim 1 of the present invention converts the electricity charged in the storage battery into alternating current and supplies all the power in the power supply area of the home, etc., so that when an abnormality occurs and the output stops The power supply area will be in a power outage state. In order to avoid this, it has the following structural features and system features.
The fail-safe inverter is used by connecting two or more DC / AC converter modules in parallel. After all the outputs of each module are combined once, it is branched again into two or more lines. It is output after passing through a switch such as a relay installed in the line. By adopting this structure, for example, when one module stops outputting due to the life of a component or the like, the remaining modules continue to output, thereby preventing output stop as an inverter.
Furthermore, since the remaining modules may be overloaded beyond their ratings, some switches of multiple outputs are shut off to prevent continuous module damage. The decision of whether to shut off any of the multiple switches is made by shutting off the low-priority line switch by using an algorithm built into the built-in microcomputer so as to make a decision according to a predetermined priority order. Normal operation can be continued.

The battery charger according to claim 2 of the present invention charges the storage battery with a power of about 500 W or less, but not only from the system power supply but also from a plurality of generators of each system including a power generation system using natural energy. It is characterized by being able to charge from a micro power generator with a rating of about 100W or less.
In addition, when there are a plurality of inputs, an algorithm that prioritizes charging by a generator other than the system power supply is provided.
According to the charger of claim 2, various general-purpose generators can be used for charging the storage battery, and the power cost can be reduced by increasing the ratio of power self-sufficiency.

The charger according to claim 3 of the present invention is characterized in that it has a temporary power storage structure inside in order to make it possible to use a micro power generator for a large capacity storage battery.
For the purpose of having a temporary storage structure, a general household and industrial storage battery has a voltage of about 200 V, so that it needs to be boosted to a higher voltage in order to be charged. In this case, with a charging power of about 100 W, the current is less than 0.5 A, and the power generation efficiency at the time of boosting becomes worse. For the purpose of assisting this boosting, a temporary power storage structure is provided, and when the amount of energy with little loss in boosting is reached, the switch of the charging line to the storage battery is closed.
According to the charger of the third aspect, a minute electric power generator can be used, and further, the amount of power self-sufficiency can be increased by charging with high efficiency, and the amount of power cost reduction can be increased.

The present invention has the above-described configuration, and has the following effects.
Even when large power is used in a power supply area such as a home, the current used from the system power supply is always kept within a rating of about 5A, so a permanent peak cut can be implemented for the system power supply.
It is possible to reduce the contract current with conventional general electric utilities etc. to about 5A, and the basic charge can be reduced.
Even when the contract current is about 5A, a large output of about 6kW can be used depending on the rated output of the inverter.
Since a plurality of facilities are not required, such as adding or stabilizing the power stabilization facility in addition to the solar panel as in the past, the initial investment can be suppressed.
It can be installed in condominiums where solar panels cannot be installed, and a smart house that reduces the environmental impact by peak cuts can be realized.
For installation, it is not necessary to redraw the wiring in the building, and it can be used almost without expanding or remodeling existing infrastructure facilities.
Since it is possible to always keep the storage battery in a fully charged state, electric power can be secured even in the event of an emergency such as a power failure or disaster.
Since it is a system that does not require grid interconnection, a simpler and cheaper inverter can be used, and the cost can be reduced.

With respect to future technical developments according to the present invention, the following further advantages can be obtained.
Since the system is installed not only in detached houses but also in homes and offices including condominiums, it is expected that the cost of storage batteries will be reduced due to mass production effects.
The market for new inverter devices with fail-safe functions is expected.
Since a generator with a rated power of about 100W can be used, in addition to the conventional low-power renewable energy generators, a new market for various other types of micro power generators is expected.

Power supply system configuration diagram according to an embodiment of the present invention Power supply system configuration diagram showing a conventional main embodiment The graph which shows the comparison of the peak cut effect with respect to the system power supply by embodiment The figure which shows the structure of the fail safe inverter in embodiment The figure which shows the example at the time of failure of the fail safe inverter in embodiment The figure which shows the multiple input structure of the charger in embodiment The figure which shows an example of the mechanical electric power temporary storage structure of the charger in embodiment The figure which shows an example of the chemical type electric power temporary storage structure of the charger in embodiment

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a power supply system configuration according to the present embodiment, and FIG. 2 shows a conventional power supply system configuration.
The power storage device 1a in FIG. 1 includes a storage battery 1b of about 10 kWh, a charger 1e with a rating of about 5A, and a fail-safe inverter 1d with a rating of about 6kW. In the conventional system, the system power supply 2e in FIG. 2 directly supplies power to the power supply area 2f such as home and office. As a feature of the present invention, the system power supply 1e is connected only to the charger 1c. Although it is used for charging the storage battery 1b, it does not supply any power to the power supply area 1f such as home and office.
All the electric power to the power supply area 1f is supplied from the electricity in the storage battery 1b via the fail-safe inverter 1d. For this reason, the electric power which can be used at home becomes the rated output voltage of the fail-safe inverter 1d.

  For each of the above figures, the capacity of the storage battery 1b of 10 kWh is used in many reports as the most standard value of the amount of power used by a general household in Japan in one day. Yes. If 10kWh is charged over a day, 416W can be obtained from 10kWh ÷ 24 hours. This is the charging power that is always required. Therefore, a charger with a rating of 500W (5A) exceeding this value was sufficient. The rated output 6 kWh of the fail inverter 1d is set from the point where the metered lamp B, which is a general household power contract, has a maximum of 60A.

FIG. 3 shows a graph for comparing the peak cut effects of the system power supply in this embodiment.
Naturally, the effects of solar power generation, which is most popular in Japan, are limited to days when the weather is good, and the environmental load on the grid power supply is almost the same as that of households that do not have a solar panel installed in the rain or at night. no change. However, in the case of the power supply system according to the present invention, the power used from the system power supply is always about 500 W (5 A) or less, and a permanent peak cut can be realized regardless of conditions such as the weather.

FIG. 4 shows the structure of the fail-safe inverter in this embodiment.
The fail-safe inverter shall use two or more DC / AC converter circuit modules 4a in parallel in order to reduce the risk of output stop due to a failure. Branches into two or more lines and outputs via a switch such as a relay installed in each line.

FIG. 5 shows the operation when the fail-safe inverter in the present embodiment is damaged.
Even when the output of one conversion circuit module 5a is stopped due to the component life or the like, in the case of this structure, the remaining modules continue to output, thereby avoiding the output stop as an inverter. However, since the power used by the power supply area may exceed the total rated value of the remaining modules, some of the output is cut off.
The switch 5c to be shut off is determined by the controller 5d according to a priority order provided in advance. By shutting off the switch 5c, the output of the conversion circuit module is maintained within the rating.

FIG. 6 shows the structure of the charger in this embodiment.
The charger 6a allows not only the power from the system power supply 6b but also the input of charging power from a plurality of generators (6d, 6e) including various power generation methods using natural energy.
For multiple inputs, inputs other than the system power supply are preferentially used for charging power for the purpose of promoting self-sufficiency of power.
Further, as a device other than the generator, charging is performed through a connection port or an attachment for charging from a small secondary battery 6f such as 18650.

7 and 8 show an example of the temporary power storage structure of the charger in this embodiment.
The charger has a temporary energy storage structure such as a spring structure or a capacitor in order to cope with a minute electric power of less than 100 W.
In the structure of FIG. 7, the minute electric power supplied from the minute electric power generator 7a is stored in the electric power temporary storage device 7d by the spring structure by the motor 7b and the speed reducer 7c, and then the energy is released at a predetermined energy amount. The storage battery 7g is charged via the generator motor 7e and the voltage conversion circuit DC / DC converter 7f.
Similarly, in FIG. 8, the minute electric power supplied from the minute electric power generator 8a is stored in the capacitor 8c, and then the energy is released at a certain amount of energy, and is supplied to the storage battery 8g via the voltage conversion circuit DC / DC converter 8f. Charged.

Claims (3)

A system for supplying power to an electric power supply area such as a home, wherein a system power source supplied from a general electric utility, a storage battery, a charger for charging the storage battery, and a DC power source of the storage battery to AC A power supply system including a power storage device including an inverter to be converted and a power supply area for homes and the like that is supplied with power through the power storage device, and further including the following features, includes the following features.
(1) The system power supply is used only for the purpose of charging the storage battery, and does not supply any power to a power supply area such as a home.
(2) All of the power supplied to a power supply area such as a home is provided by power from the storage battery via the inverter. In addition, the inverter that will be responsible for all of the supplied power is equipped with two or more parallel module structures and two or more output terminals as a fail-safe function to enhance breakage durability, making it a priority for the load used The output can be controlled accordingly.   The charger for charging the storage battery has two or more inputs of the system power generator and each type of generator including the generation method by natural energy, and the storage battery is charged by a small power generator of about 100 W or less. 2. The power supply system according to claim 1, further comprising a control for giving priority to a plurality of inputs other than the system power supply. 3. The power supply system according to claim 2, further comprising: a charger having one of the following temporary power storage functions for charging the storage battery with electric power from the minute power generator.
(1) A spring, a flywheel, or a mechanical structure that uses a fluid such as gas or molten salt.
(2) A battery having a chemical structure utilizing a small capacity secondary battery or capacitor.